Paper machine



March 17,1942. 0. ROLLS 2,276,877

' I PAPER MACHINE Filed Jan. 21, 1957 Patented Mar. v1"7, 1942 Application January 21, 1937,, Serial No. 121,502

' In Norway January 17, 1936 1; Claims.

In paper-machines which run at high speeds difliculties are caused by air bubbles or foam on the wire-cloth which form thin and transparent spots in the paper. For-destroying such air bub bles it is usual to blow hot air or steam against the paper web on the wire-cloth, or water jets may be employed.

Such air bubbles are formed by the wire-cloth, which moves at a high rate of speed over the breast-roller and past the mouth of the pulp outlet through which the pulp supplied,to the upper side of the wire-cloth, carrying along air 'through the narrow space between the breastroller and the pulp outlet and past the mouth of the latter to the lower side of the web of pulp delivered to the wire-cloth. It is the object of the present invention to prevent air bubbles from being formed in this manner. This object is attained by submitting the space immediately'in front of the pulp outlet to a reduced air pressure.

For this purpose there is provided below the out- In the construct onal form in Fig. 1, there is provid a packing member I of rubber or other material, the surface of which adjacent by the wire-cloth is wiped 011 in front of the said the wire-cloth on the breast-roller 2 is provided with a series of grooves extending in a direction parallel to the axis of the roller, and thus formsan interleaving seal, so that water carried along member I and forms a water seal at the entrance edge thereof. The said packing member I is adjustable by means of screws 3, so that it may be adjusted in diiferent positions relatively to the breast-roller. Attached to the opposite sides of the brackets III are end members or closures in contact with the same" If desired, these rublet and in front of the upward moving portion 5 of the breast-roller covered by the wire-cloth, a closed chamber or box in which a reduced air pressure can be maintained, and one wall of .which is formed by the surface of said breastroller, said chamber or box extending to the space between the pulp outlet and the wire-cloth, so that the wire-cloth runs through the said chamber -just before it moves'in below the saidoutlet. By maintaining a sumciently reduced air pressure in said chamber or box there will be no flow of air in the direction of movement of the which form'a chamber or box, such-V end pieces being held in an airtight manner against the rigid portions of the box, while the packings against the breast-roller 2 are made of an elastic material, preferably rubber, which extends close to the roller withoutnecessarily being quite ber packings are made of a large width, so that interleaving. seals may be formed by providing them with suitable grooves. 1 I

'The chamber 5 thus formed on the upward moving portion of the breast-roller, and which extends to the angle or space formedbetween the lower wall 4 of the pulp outlet and'the wire- Y cloth running "over thebreast-roller, be

wire-cloth, and no air will be carried along by the wire-cloth passing through the chamber or box to the pulp delivered by the outlet to the wire-cloth.

evacuated to some extent due to the airpumping action of the wire-cloth passing at ahigh rate of speed through the chamber, and maybe fur ther evacuated through a pipe iprovided with a regulating valve, by means of a suction pump, which is not illustrated in the drawing, and which may be the suction pump that is used for .the suction boxes for the wire-cloth. From the The chamber may be provided with a packing member forming a portion of its wall and located in close proximity to or in contact with the wirecloth on the breast-roller, and said packing member may be provided with a series of grooves ex-- tending in the axial direction of the breast-roller and which act as an interleaving seal against the wire-cloth.

Suchpacking member may also consist of a roller which rolls against the wire-cloth on thebreast-roller, and against the side of which remote from the wire-cloth a member bears to provide the necessary tightness on this side.

r The invention is illustrated in the accompanying drawing,in which Figs. 1 and 2 illustrate diagrammatically two different constructional forms of the invention embodied in a machine of the Fourdrinier type.

bottom of the chamber 5 .a drain pipe. I, also'provided with a regulating valve, leads to a receptacle positioned at a lower level; and which may be esame receptacle that receives the water from the wire-cloth suction boxes, and down into which the said pipe I must always reacli so far that a water seal is formed that prevents admission of air. I

In the constructional form of the invention illustrated in Fig. -2, which is the preferred form when sufllcient space is available, there'is provided, instead of the-stationary packing member I, a roller 8 which is suitably covered with rubher, and which rolls against the wire-cloth on the breast-roller and presses out air andwater, thus forming a water'seal in front of theroller. In this case tightness is obtained'on the'other side of the roller I by means of a stationary plate 9,

2 career? which against the roller 8, and which forms anair-tight seal between said roller and the stationarywall llofthebox; 1

Also in this constructional form of the invention evacuation of the box is unnecessary under certain conditions, .since, owing to the high speed wall of said vacuum box, and a packing member of the wire-cloth, a vacuum is formed to the rear of the roller 8. It is suitable, however, to

provide a controlled drain pipe 1, as in the constructional form illustrated in Big. 1, and ii desired, removal of air from the chamber 5 may be effected, for instance, by conducting wastewater through an injector.

- Fig. 2 also shows av third constructional form which is simpler but less eflicient, and accord ing to which, a packing member ll, preferably formed as an interleaving seal of suitable extension in the peripheral direction, is provided directly below the lower side of the pulp outlet 4.

In such case the roller I and plate 8 are omitted,

and the suction box is formed only of the said interleaving ,seal. -A water seal is formed in front of the same by the water carried along by the wlre'cloth.

I claim:

1-. In a paper-machine of the Fourdrinier type,

the combination of a breast-roll, a wire-cloth running over said breast-roll, a pulp outlet for supplying pulp to said wire-cloth above said breast roll, and a vacuum box located below said pulp outlet in front of the upward moving portion of said breast-roll, a portion of the surface 01' said breast-roll forming a wall of said vacuum box.

2. In a paper-machine of the Fourdrinier type, the combination of a breast-roll, a wire-cloth running over said breast-roll, a pulp outlet for s pplying pulp to said wire-cloth above said breast-roll, a box located below said pulp outlet in front of the upward moving portion of said breast-roll, a portion of the surface of saidbreast-roll'forming a wall of said vacuum box,

and means, other than the r'novingfwire-cloth,

for evacuating said vacuum box.

3, In a paper-machine of the Fourdrinier type,

the combination of a breast-roll, a wire-cloth running over said breast-roll, a pulp' outlet for said roller.

5 3 91111 8 pulp in said wire-cloth, a vacuum box located below saidpulp outlet in front of the upward moving portion of said breast-roll, a portion 'of the surface of said breast-roll forming a wall of said vacuum box, and a packing membet in' saidvacuum box adjacent the wire-cloth on said breast-roll.

4. In a paper-machine of the Fourdrinier type the combination of a breast-roll, a wire-cloth running over said breast-roll, a pulp outlet for located below said pulp outlet in'fmnt of the upward moving portion of said'breast-roll, a portionof the surface of said breast-roll forming a upward moving portion of ,said breast-roll, a porin said vacuum box adjacent the wire-cloth on said breast-roll, said packing member being provided on its surface directed towards said wirecloth with a series of substantially parallel grooves forming an interleaving seal against said wire-cloth.

5. In a paper-machine of the Fourdrinier type,

the co bination of a breast-roll, a wire-clothrunnin over said breast-roll, a pulp outlet for suppl g pulp to said wire-cloth, a vacuum box located below said pulp outlet in front of the" upward moving portion of said breast-roll, a portion of the surface of said breast-roll forming a wall of said-vacuum box, a packing member in said vacuum 'boxadjacent the wire-cloth on said breast-roll, and means for adjusting said packing member relatively to said breast-roll.

1 6. In a paper-machine of the Fourdrinier type, the combination of a breast-roll, a wire-cloth running over said breast-roll, a pulp outlet for supplying pulp to said wire-cloth, a vacuum box located'below said pulp outlet in front ofthe upward moving portion of said breast-roll, a portion of the surface of said breast-roll forming a wall of said' vacuum box, and a packing member in said vacuum box adjacent the wire-cloth on said breast-roll, said packing member consisting of a rotatably journalled. roller adapted to roll against said wire-cloth on said breast-roll.

7, In a paper-machine of the Fourdrinier type,

the combination of a breast-roll, a'wire-cloth running'over said breast-roll, a pulp outlet for supplying pulpto said wire-cloth, a vacuum box located below said pulp outlet in front of the upward moving portion of said breast-roll, a portion of the surface of said breast-roll forming a wall of said vacuum box, a packing member insaid vacuum box adjacent the wire-cloth on said breast-roll, said packing member consisting of a rotatably journalled roller adapted to roll against said wire-cloth on said breast-roll, and a member forming a portion of the wall of said vacuum box and located on theside of said roller remote from said wire-cloth and contacting with said tion of the surface of said breast-roll forming a supplying pulp to said wire-cloth, a vacuum box- I wall of said vacuum box, a packing member in said vacuum box adjacent the wire-cloth on said breast-roll, said packing member consisting of a rotatably iournalled'roller adapted to roll against said wire-cloth on said breast-roll, and additional means for evacuating said vacuum box.

OSCAR ROLLS. 

